Impulse-actuated rock drill



May 13, 1924. 1,494,030

F. M. SLATER IMPQLSE ACTUATED ROCK DRILL Filed July 2o. 1921 MAM ATTQRN Y Patented May 13, 1924.

UNITED STATES taime PATENT OFFICE.

FRED M. SLATER, OF EASTON, PENNSYLVANTA, ASSIGNOR TO NGERSOLL-RAND COM- PANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

IMPULSE-ACTUATED ROCK DRILL.

Application filed July` 20, 1921. Serial N'o. 486,228.

To all whom t may concern.'

Be it known that I, FRED `M. SLATER, a. citizen of the United States, a resident of Easton, county of Northampton, and State of Penns lvania, have invented a certain Impulsectuated Rock Drill, of which the following is a specification accompanied by drawings.

This invention relates to ay fluid pressure rock drill of the hammer type, in which the hammer piston may be actuated forwardly by intermittent impulses of motive fluid pressure admitted to and ,exhausted from the cylinder rearwardly of the piston.

In my copending application, Serial No. 486,227, led July 20, 1921, I have disclosed a iiuid pressure impulse system having an interrupter forming a part of the iiuid supply for generatingy and controlling the fluid impulses for operating a` rock drillor other machine and one of the objects of the present invention is to enable a rock drill of the type disclosed in that application to be operated by means of impulsesgenerated and controlled by a device mounted upon and forming a part of the machiney itself, so that the apparatus is unitary and self contained and may be connected to the system disclosed in said copending application or may out the interposition of any special piece apparatus between the source of' supply and the rock drill.

Further objects of the invention are to improve upon machines, especially `rock drills of the impulse type, economize motive fluid pressure and 'increase the efficiency of the machine. r

To all of these ends the invention consists of the machine shown in the accompanying drawings in one of its preferred forms, in which- Figure 1 is a longitudinal sectionalside view of a rock drill.

Figure 2 is a similar view with the piston at the forward end of its stroke, and

Figure 3 1s a similar view partly broken away with the piston atthe rearward end of its stroke.

D. Apiston E is provided with a main head` be connected to any usual supply line with- Referring to the drawings, the cylinder A y is formed witha main bore B, and a guiding p F, reciprocating in the main cylinder bore B, and a reduced shank G guided in the ore C.

.The shank H of the hollow drill steel VJ extends within the chuck K, in the front head L, in position to receive the blows of impact of the fluted end O' of the hammer, slidable in the chuck K but in non-rotatable engagement therewith. qRotation `may be imparted to the piston and drill steel by means of the usual rifle bar P, having the ratchet Q in the back head R, to which the handle S is connected.

A distribution ort T is located at the rear end of the cy inder A, and a casing U, which may be separate from the cylinder A or an integral part of the cylinder, as shown, contains a device which may be in the form of a pressure actuated valve V, for controlling the` impulse of fluid pressure for actuating the piston forwardly.` In `this instance, the fluid impulses are both admitted through and exhausted from the same distribution port T for convenience, and the main supplyline W through which air .un- A controllig valve head ai is connected to the casing at the 'admission port X. The exhaust from behind the piston takes place through the exhaust port Y, from which it sion port X in the casing U is opened to mon tive fluid pressure, the valve V will assume the'position indicated in Figure l, and an impulse ofmotive fluid will vbe admitted to the cylinder rearwardly of thelmain piston head1?. `Theimmediate closing of the valve V yin a manner to be disclosed, interrupts or cuts `off the supply of fluid pressure to the cylinder andthe reciprocation of the valve V in the valve chest lU controls fluid pres ,sure impulses for operating the piston in a forward direction.

A.' passage g, leading from the rearward to the forwardposition of the cylinder,per

mits a portion of a iiuid impulse, which actuatesthe piston forwardly, to pass to the CII ton head F and expansion of the motive.

lluid serves as the sole means for returning the piston on its rearward stroke when the pressure behind the piston is exhausted through port Y. rlhe pressure in .front of the piston head F, communieated to the head Z of the controlling valve V through the passage c, moves said valve to the position indicated in Figure 2.. as the piston reaches the end of .its forward stroke, fopening the exhaust from behind the piston through the port Y, which lmaybey'connected to the intake of the compressor land;relieving the pressure behind the pistonhead on the return stroke. It is obvious that the: eX- haust Y may exhaust intothe atmosphere, in which case the compressor will he obliged todraw in fresh air at 4each fst'roke.

Means are` provided for exhaustingthe pressure from in front of the main piston head F when the piston reaches the .end of its rearward travel, andI prefer to eX- haust'l the `fluid though the front, end` of the machine and through the' hollow drill steel J for blowing out4 the drill hole.v For this purpose, the reducedshank Aofthe pistonv is preferably provided 'with a beveled shoulder g, which arrives',oppositev the preferably beveled end#q of the'borefC ',.thewhlls'hing D when the piston [reaches the "end 'of its rearward travel, so ythatfthfe 'fluidf'may 4be exhausted throughfthe boreCand thefflute'd shank O of the piston, tozthie lfrontendof the machine and thence through the drill steel.

In the operation ol the machine', let it be assumed that the piston is traveling on Vitsforward stroke and is inthe position indicated in Figurev l, at which'point:thefpassage v(l. leading to the forward end of the cylinderl is uncovered` bythe `pistonhead F. An impulse of motive fluid hasbfeen ad-` mitted throughthe 'rear 'disfvtribiitionport T of the cylinder,. and is lactin'giiponmthe larger pressure. areamof th'e'main head ;F of the piston., The interrupter valve V is in the position indicated,"andithejexhaust Y is closed.y As the `piston freaches'thegend of its forwardstroke3 "asindicatedfinlFig-` ure i2, the valve Y is thrown fitsv 'opposite position cutting` yolf the supply and'op'ening the exhaust Y to theirear,end .ofthe cylinder. The ezipansion of thefmotive fluid in front ofi the main piston `headl?ieturns 'the Pisten ollltereerwid .Stllejtothe p0?l Vsition indicated yin `Figure; 35j at which point y the* forwardfend of fthejcylinfder is.` eviliaustthrown to the position indicated in Figure l, admitting another impulse of motive liuid to the cylinder and the cycle is repeated.

claim:

l. An impulse actuated fluid pressure rock drill of the hammer type, comprising a cylinder having a main bore7 a piston having' a head and a reduced shank? means for actuating the piston forwardly by impulses of motive fluid intermitentlxv introduced rearwardly7 of said piston head, a :forward volume `chamber in the cylinder communicating with the :foward end of the mainbore, means for passing a portion of each impulse of motive fluid to the forward` end of the cylinder and the volume chamber including means for 'trapping said portion ofthe motive fluid at the forward end of the cylinder serving asthe sole. means forv returning the y piston on yits rearward stroke.l and fluid actuated means in communication with a constant pressure `supply mounted on the cylinder for cont-rolling the said actuating impulses ofp'rmotive Vfluid and for exhausting the cylinder rearwardly of fthe pistonhead for theJ return stroke of 'the piston. y

2. An impulse actuated yfluid pressure rockl drill of the hammer type, comprising a vcylinder having a main bore, a vpiston having a head and a reduced shank,.'means for actuating the( piston forwardly by impulses o'f motive fluid intermittently introduced rearwardly of. said piston head.` a forward volume y chamber in the cylinder communicaringl with) the lforward en'd of "the main, bore,rnefans.` for passmga 'portion 'of Veach impulseofv motive fluid to the forward, 'end of theA cylinder andthe volume 4chamber including means for trapping'said portion 'ofthe motive fluid at the forward endof the'cyhnder serving as the solemeans for returning `the 'piston on its rearwardk stroke, fluid` actuated means in communication withv a constant pressure supply iounted on'the cylinder for cont-rolling the said actuating impulses of motive lfluid and lfor'exhausting the cylinder rearwardly of thepiston head for .the return stroke of the piston, and'mean's 'controlled'by the pistonl for exhausting the'lui'd trapped in ,front ofthe 'piston head and I'in the volumechamber.

3. An impulse lactuated fluid pressure rock drillof the hammer type, comprising. a cylinder having amain boreand Va guiding a bore of 'reduced diameter, la piston having a headnin the main bore land a reduced shank 'guidedin the reduced b'o're, an interrupter 4in lcommunication with a constant supply of pressure n fluid mounted ou l the cylinder for intermittently Vcontrolling impulses yof motive fluid and admitting and exhausting said impulses lo'fnuoliive` ljuidA rearwardly "of 'the piston head, a 'forward volume chamber Cil in the cylinder separate from and independent of the cylinder bore and communicating with the forward end of the main bore, a passage for passing a portion of each impulse of motive Huid to the forward end of the cylinder and the volume chamber and a valve for closing said passage and trapping said portion of the motive fluid in the cylinder after the piston has travelled a portion of its forward stroke, the expansion of the fluid from the volume chamber serving as the sole means for actuating said piston rearwardly.

4c. An impulse actuated fluid pressure rock drill of the hammer type comprising a cylinder having a main bore and a bore of reduced diameter, a piston reciprocating in the cylinder having a head in the main bore and a forwardly extending'reduced shank guided in the bore of reduced diameter, a volume chamber in the forward end of the cylinder around the reduced bore but separate and independent therefrom and communicating with themain cylinder bore, said cylinder having a distribution port at the rear end of the main bore and a supply passage leading from the rear to the front of the main bore, a valve controlling said supply passage, a casing on the cylinder and an interruptertherein nvcommunication with a constant supply of pressure fluid for controlling impulses of motive fluid from the supply through the said rear cylinder distribution port and for exhausting the main bore behind the piston head, the impulses of motive Huid behind the piston head driving the piston forward, and the` expansion of Huid trapped in front of the piston head and in the volume chamber serving as the sole means for returning the piston on its rearward stroke.

In testimony whereof I have signed this specification.

FRED. M. `-SLATER. 

